Surface cleaning apparatus with dirt arrester having an axial step

ABSTRACT

A surface cleaning apparatus has a cyclone chamber having a longitudinal cyclone axis of rotation wherein the dirt outlet is defined at least in part by a gap between the sidewall of the cyclone and a plate positioned at the dirt outlet end of the cyclone. The plate is stepped in the axial direction.

FIELD

This disclosure relates generally to surface cleaning apparatus. In a preferred embodiment, the surface cleaning apparatus comprises a cyclonic separator including a plate (also referred to as an arrester plate) at the dirt outlet and of a cyclone chamber wherein the plate has an axial step.

INTRODUCTION

The following is not an admission that anything discussed below is part of the prior art or part of the common general knowledge of a person skilled in the art.

Various types of surface cleaning apparatus are known. Such surface cleaning apparatus include vacuum cleaners, including upright vacuum cleaners, hand carriable vacuum cleaners, canister-type vacuum cleaners and Shop-Vac™ type vacuum cleaners. Some vacuum cleaners include a cyclonic separator (also referred to as a cyclone bin assembly) having a cyclone chamber, a dirt collection chamber, and a plate at the dirt outlet end. See for example Conrad (U.S. Pat. No. 8,640,304).

SUMMARY

This summary is intended to introduce the reader to the more detailed description that follows and not to limit or define any claimed or as yet unclaimed invention. One or more inventions may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures.

According to a first aspect of this disclosure, which may be used by itself or in combination with one or more other aspects of this disclosure, a cyclone is provided at the dirt outlet end of the cyclone chamber with a plate that is stepped in the axial direction. The dirt outlet is defined at least in part by a gap between the plate and the sidewall of the cyclone chamber. Stepping the plate in the axial direction enables a portion of the plate to define a larger dirt outlet so as to enable larger dirt to exit the cyclone chamber.

In accordance with this aspect, there is provided a surface cleaning apparatus comprising:

-   (a) an air flow path extending from a dirty air inlet to a clean air     outlet; -   (b) a cyclone and a suction motor provided in the air flow path; -   (c) the cyclone comprising a cyclone chamber having a central     longitudinal axis, the cyclone having a first end having a first end     wall, an axially spaced apart second end, a cyclone chamber sidewall     located between the first and second ends, a cyclone air inlet     provided at the first end, a cyclone air outlet provided at the     first end and a dirt outlet provided at the second end, wherein a     reference plane that is perpendicular to the central longitudinal     axis extends through the cyclone chamber; and, -   (d) a plate located at the second end, the plate having a plate     perimeter, a first portion,     -   (i) a second portion and a transition portion provided between         the first and second portions, each of the first, second and         transition portions of the plate having a cyclone chamber face         wherein the cyclone chamber faces of the first and second         portions of the plate face towards the first end and border         different portions of the plate perimeter,     -   (ii) the second portion is spaced in a direction parallel to the         central longitudinal axis further from the reference plane than         the first portion,     -   (iii) the dirt outlet comprises a spacing between the cyclone         chamber sidewall and the second portion of the plate,     -   (iv) the plate also having a dirt chamber face and a step         volume, the step volume positioned axially between the cyclone         chamber faces of the first and transition portions and the dirt         chamber face whereby the dirt chamber face comprises a closure         portion which underlies the step volume; and, -   (e) a dirt collection region in communication with the cyclone     chamber via the dirt outlet.

In any embodiment, the closure portion may extend at an angle to the central longitudinal axis.

In any embodiment, the first portion of the plate may be thicker than the second portion of the plate.

In any embodiment, a thickness of the first portion of the plate may increase towards the transition portion of the plate.

In any embodiment, a first discontinuity may be provided between the cyclone chamber face of the first portion of the plate and the cyclone chamber face of the transition portion and a second discontinuity may be provided between the cyclone chamber face of the transition portion and the cyclone chamber face of the second portion of the plate.

In any embodiment, the transition portion may extend generally axially.

In any embodiment, the first portion of the plate and the second portion of the plate may be generally planar.

In any embodiment, the dirt chamber face of the plate may be generally continuous.

In any embodiment, the dirt collection region may be axially spaced from and opposed to the first end of the cyclone.

In any embodiment, the closure portion may be planar.

In any embodiment, the closure portion may extend from a first end proximate a dirt chamber face of the second portion towards or across the central longitudinal axis to a second end, and the first end of the closure portion may be laterally spaced from the second end of the closure portion.

In accordance with this aspect, there is also provided a surface cleaning apparatus comprising:

-   -   (a) an air flow path extending from a dirty air inlet to a clean         air outlet and including a cyclone chamber and a suction motor;     -   (b) a dirt collection region external to the cyclone chamber;         and,     -   (c) a plate positioned between the cyclone chamber and the dirt         collection region and defining a dirt outlet from the cyclone         chamber to the dirt collection region, the plate having a         cyclone chamber face facing the cyclone chamber, an opposed dirt         collection face facing the dirt collection region, and first,         second, and transition portions, wherein cyclone chamber faces         of the first and second portions are connected by a cyclone         chamber face of the transition portion and are different axial         distances from a transverse plane that extends through the         cyclone and that is perpendicular to a central longitudinal axis         of the cyclone, and the dirt collection face closes a step         volume bordered by the first and transition portions.

In any embodiment, the first portion of the plate may be thicker than the second portion of the plate.

In any embodiment, the dirt chamber face of the plate may be generally continuous.

In any embodiment, the dirt collection region may be axially spaced from and opposed to the first end of the cyclone.

In any embodiment, a first discontinuity may be provided between the cyclone chamber face of the first portion of the plate and the cyclone chamber face of the second portion of the plate.

In any embodiment, the first portion of the plate and the second portion of the plate maybe generally planar.

In any embodiment, the closure portion may extend at an angle to the central longitudinal axis.

In any embodiment, the closure portion may be planar.

In any embodiment, the closure portion may extend from a first end proximate a dirt chamber face of the second portion towards or across the central longitudinal axis to a second end, and the first end of the closure portion may be laterally spaced from the second end of the closure portion.

In accordance with another aspect, there is provided surface cleaning apparatus comprising:

-   -   (a) an air flow path extending from a dirty air inlet to a clean         air outlet     -   (b) a cyclone provided in the air flow path, the cyclone         comprising a cyclone chamber, a cyclone air inlet, a cyclone air         outlet, a dirt outlet, a central longitudinally extending axis,         the cyclone chamber having first and second axially opposed         ends;     -   (c) a suction motor positioned in the air flow path;     -   (d) a dirt collection region external to the cyclone chamber;         and,     -   (e) a plate positioned at the second end of the cyclone chamber,         the plate having a cyclone chamber face facing the cyclone         chamber, the cyclone chamber face having first and second         portions, wherein the first portion of the cyclone chamber face         and the second portion of the cyclone chamber face are different         axial distances from a transverse reference plane that extends         through the cyclone chamber and that is perpendicular to the         central longitudinally extending axis of the cyclone, wherein an         annular gap between the plate and the cyclone extends around all         of the plate and defines the dirt outlet of the cyclone chamber.

In any embodiment, the annular gap may have a radial distance between the plate and the cyclone and the radial distance may be constant.

In any embodiment, the annular gap may have a radial distance between the plate and the cyclone and the radial distance may vary at different locations around the plate.

In any embodiment, the plate may have a perimeter and the perimeter may extend generally continuously.

In any embodiment, the plate has a perimeter and the perimeter has two discontinuities.

In any embodiment, the plate may have a segment removed. Optionally, the annular gap may have a radial distance between the plate and the cyclone, the radial distance may vary at different locations around the plate and the radial distance may be increased at a location of the plate from which the segment has been removed. Alternately, or in addition, the second portion may be a greater axial distance from the transverse plane than the first portion and the location of the plate from which the segment has been removed may be the second portion.

In any embodiment, the second portion may be a greater axial distance from the transverse plane than the first portion and the second portion has a segment removed. Optionally, the annular gap may have a radial distance between the plate and the cyclone and the radial distance may be increased at a location of removal of the segment.

In any embodiment, the plate may be positioned between the cyclone chamber and the dirt collection region, the plate may have a dirt collection face facing the dirt collection region.

In any embodiment, the cyclone air inlet and the cyclone air outlet may be provided at the first end of the cyclone chamber, the cyclone air outlet may comprise a vortex finder and porous member positioned between the cyclone chamber and an inlet of the vortex finder, and the vortex finder and porous member may be spaced from the cyclone chamber face of the plate.

In any embodiment, the plate may be moveably mounted between a closed position, in which the plate is positioned for operation of the cyclone and an open position wherein the plate is moved to provide access to the cyclone chamber.

In any embodiment, the dirt collection region has an end wall facing the plate and the end wall may be openable. Optionally, the plate may be supported by the end wall and is moveable with the end wall.

In any embodiment, the plate has a dirt collection face facing the dirt collection region and the surface cleaning apparatus may further comprise a support member extending between the end wall and the dirt collection face. Optionally, the cyclone air inlet and the cyclone air outlet may be provided at the first end of the cyclone chamber, the cyclone air outlet may comprise a vortex finder and porous member positioned between the cyclone chamber and an inlet of the vortex finder, and the vortex finder and porous member may be spaced from the cyclone chamber face of the plate.

In any embodiment, the plate has a perimeter, the cyclone has a generally axially extending sidewall and the annular gap may be provided between the perimeter of the plate and the sidewall.

In any embodiment, the cyclone has an axially extending sidewall and the sidewall has an end face and at least a portion of the end wall may face the plate.

Optionally, the plate has a perimeter, the dirt collection region has a sidewall and the annular gap may be provided between the perimeter of the plate and the sidewall.

DRAWINGS

The drawings included herewith are for illustrating various examples of articles, methods, and apparatus of the teaching of the present specification and are not intended to limit the scope of what is taught in any way.

In the drawings:

FIG. 1 is a perspective view of a surface cleaning apparatus in accordance with an embodiment;

FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1;

FIG. 3 is a cross-sectional view taken along line 2-2 in FIG. 1 of a cyclone bin assembly of the surface cleaning apparatus of FIG. 1 when removed from the remainder of the surface cleaning apparatus;

FIG. 4 is a top perspective view of an arrester plate of the cyclone bin assembly of FIG. 3;

FIG. 5 is a bottom perspective view of the arrester plate of FIG. 4;

FIG. 6 is the cross-sectional view of FIG. 3 with the cyclone bin assembly in an open position;

FIG. 7 is a cross-sectional view of a cyclone bin assembly having an arrester plate in accordance with another embodiment;

FIG. 8 is a cross-sectional view of a cyclone bin assembly having an arrester plate in accordance with another embodiment;

FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 8;

FIG. 10 is a cross-sectional view taken along line 9-9 in FIG. 8 with an arrester plate in accordance with another embodiment;

FIG. 11 is a cross-sectional view a cyclone bin assembly with an arrester plate in accordance with another embodiment;

FIG. 12 is a top perspective view of the arrester plate of the cyclone bin assembly of FIG. 11;

FIG. 13 is a bottom perspective view of the arrester plate of the cyclone bin assembly of FIG. 11;

FIG. 14 is a cross-sectional view a cyclone bin assembly with an arrester plate in accordance with another embodiment;

FIG. 15 is a top perspective view of the arrester plate of the cyclone bin assembly of FIG. 14;

FIG. 16 is a bottom perspective view of the arrester plate of the cyclone bin assembly of FIG. 14;

FIG. 17 is a cross-sectional view a cyclone bin assembly with an arrester plate in accordance with another embodiment;

FIG. 18 is a top perspective view of the arrester plate of the cyclone bin assembly of FIG. 17; and,

FIG. 19 is a bottom perspective view of the arrester plate of the cyclone bin assembly of FIG. 17.

DESCRIPTION OF VARIOUS EMBODIMENTS

Various apparatuses, methods and compositions are described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover apparatuses and methods that differ from those described below. The claimed inventions are not limited to apparatuses, methods and compositions having all of the features of any one apparatus, method or composition described below or to features common to multiple or all of the apparatuses, methods or compositions described below. It is possible that an apparatus, method or composition described below is not an embodiment of any claimed invention. Any invention disclosed in an apparatus, method or composition described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicant(s), inventor(s) and/or owner(s) do not intend to abandon, disclaim, or dedicate to the public any such invention by its disclosure in this document.

The terms “an embodiment,” “embodiment,” “embodiments,” “the embodiment,” “the embodiments,” “one or more embodiments,” “some embodiments,” “one embodiment”, and the like mean “one or more (but not all) embodiments of the present invention(s),” unless expressly specified otherwise.

The terms “including,” “comprising” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. A listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an” and “the” mean “one or more,” unless expressly specified otherwise.

As used herein and in the claims, two or more parts are said to be “coupled”, “connected”, “attached”, “joined”, “affixed”, or “fastened” where the parts are joined or operate together either directly or indirectly (i.e., through one or more intermediate parts), so long as a link occurs. As used herein and in the claims, two or more parts are said to be “directly coupled”, “directly connected”, “directly attached”, “directly joined”, “directly affixed”, or “directly fastened” where the parts are connected in physical contact with each other. As used herein, two or more parts are said to be “rigidly coupled”, “rigidly connected”, “rigidly attached”, “rigidly joined”, “rigidly affixed”, or “rigidly fastened” where the parts are coupled so as to move as one while maintaining a constant orientation relative to each other. None of the terms “coupled”, “connected”, “attached”, “joined”, “affixed”, and “fastened” distinguish the manner in which two or more parts are joined together.

Furthermore, it will be appreciated that for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the example embodiments described herein. However, it will be understood by those of ordinary skill in the art that the example embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the example embodiments described herein. Also, the description is not to be considered as limiting the scope of the example embodiments described herein.

General Description of a Vacuum Cleaner

Referring to FIGS. 1-2, an exemplary embodiment of a surface cleaning apparatus is shown generally as 100. The following is a general discussion of apparatus 100 which provides a basis for understanding several of the features which are discussed herein. As discussed subsequently, each of the features may be used individually or in any particular combination or sub-combination in this or in other embodiments disclosed herein.

Embodiments described herein include an improved cyclone assembly 116, and a surface cleaning apparatus 100 including the same. Surface cleaning apparatus 100 may be any type of cyclonic surface cleaning apparatus, including for example a hand vacuum cleaner, a stick vacuum cleaner, a canister vacuum cleaner, and an upright vacuum cleaner.

In FIGS. 1-2, surface cleaning apparatus 100 is illustrated as a hand vacuum cleaner, which may also be referred to also as a “handvac” or “hand-held vacuum cleaner”. As used herein, a hand vacuum cleaner is a vacuum cleaner that can be operated to clean a surface generally one-handedly. That is, the entire weight of the vacuum may be held by the same one hand used to direct a dirty air inlet of the vacuum cleaner with respect to a surface to be cleaned. For example, handle 104 and dirty air inlet 108 may be rigidly coupled to each other (directly or indirectly), such as being integrally formed or separately molded and then non-removably secured together such as by an adhesive or welding, so as to move as one while maintaining a constant orientation relative to each other. This is to be contrasted with canister and upright vacuum cleaners, whose weight is typically supported by a surface (e.g. a floor) during use, and when a canister vacuum cleaner is operated or when an upright vacuum cleaner is operated in a ‘lift-away’ configuration, a second hand is typically required to direct the dirty air inlet at the end of a flexible hose.

Still referring to FIGS. 1-2, surface cleaning apparatus 100 includes a main body 112 having an air treatment member 116 (which may be permanently affixed to the main body or may be removable therefrom for emptying), a dirty air inlet 108, a clean air outlet 120, and an air flow path 124 extending between the dirty air inlet 108 and the clean air outlet 120.

Surface cleaning apparatus 100 has a front end 128, a rear end 132, an upper end (also referred to as the top) 136, and a lower end (also referred to as the bottom) 140. In the embodiment shown, dirty air inlet 108 is at an upper portion of apparatus front end 128 and clean air outlet 120 is at a rearward portion of apparatus 100 at apparatus rear end 132. It will be appreciated that dirty air inlet 108 and clean air outlet 120 may be positioned in different locations of apparatus 100.

A suction motor 144 is provided to generate vacuum suction through air flow path 124, and is positioned within a motor housing 148. Suction motor 144 may be a fan-motor assembly including an electric motor and impeller blade(s). In the illustrated embodiment, suction motor 144 is positioned in the air flow path 124 downstream of air treatment member 116. In this configuration, suction motor 144 may be referred to as a “clean air motor”. Alternatively, suction motor 144 may be positioned upstream of air treatment member 116, and referred to as a “dirty air motor”.

Air treatment member 116 is configured to remove particles of dirt and other debris from the air flow. In the illustrated example, air treatment member 116 includes a cyclone assembly (also referred to as a “cyclone bin assembly”) having a single cyclonic cleaning stage with a single cyclone 152 and a dirt collection chamber 156 (also referred to as a “dirt collection region”, “dirt collection bin”, “dirt bin”, or “dirt chamber”). Cyclone 152 has a cyclone chamber 154, and dirt collection chamber 156 may be external to the cyclone chamber 154 (i.e. dirt collection chamber 156 may have a discrete volume from that of cyclone chamber 154). Cyclone 152 and dirt collection chamber 156 may be of any configuration suitable for separating dirt from an air stream and collecting the separated dirt, respectively and may be in communication by a dirt outlet of the cyclone chamber.

In alternate embodiments, air treatment member 116 may include a cyclone assembly having two or more cyclonic cleaning stages arranged in series with each other. Each cyclonic cleaning stage may include one or more cyclones arranged in parallel with each other and one or more dirt collection chambers, of any suitable configuration. The dirt collection chamber(s) may be external to the cyclone chambers of the cyclones. Alternatively, one or more (or all) of the dirt collection chamber(s) may be internal to one or more (or all) of the cyclone chambers. For example, the internal dirt collection chamber(s) may be configured as a dirt collection area within the cyclone chamber.

Referring to FIG. 2, hand vacuum cleaner 100 may include a pre-motor filter 160 provided in the air flow path 124 downstream of air treatment member 116 and upstream of suction motor 144. Pre-motor filter 160 may be formed from any suitable physical, porous filter media. For example, pre-motor filter 160 may be one or more of a foam filter, felt filter, HEPA filter, or other physical filter media. In some embodiments, pre-motor filter 160 may include an electrostatic filter, or the like. As shown, pre-motor filter 160 may be located in a pre-motor filter housing 164 that is external to the air treatment member 116.

In the illustrated embodiment, dirty air inlet 108 is the inlet end 168 of an air inlet conduit 172. Optionally, inlet end 168 of air inlet conduit 172 can be used as a nozzle to directly clean a surface. Alternatively, or in addition to functioning as a nozzle, air inlet conduit 172 may be connected (e.g. directly connected) to the downstream end of any suitable accessory tool such as a rigid air flow conduit (e.g., an above floor cleaning wand), a crevice tool, a mini brush, and the like. As shown, dirty air inlet 108 may be positioned forward of air treatment member 116, although this need not be the case.

In the embodiment of FIG. 2, the air treatment member comprises a cyclone 152, the air treatment air inlet is a cyclone air inlet 184, and the air treatment member air outlet is a cyclone air outlet 188. Accordingly, in operation, after activating suction motor 144, dirty air enters apparatus 100 through dirty air inlet 108 and is directed along air inlet conduit 172 to the cyclone air inlet 184. As shown, cyclone air inlet 184 may direct the dirty air flow to enter cyclone chamber 154 in a tangential direction so as to promote cyclonic action. Dirt particles and other debris may be disentrained (i.e. separated) from the dirty air flow as the dirty air flow travels from cyclone air inlet 184 to cyclone air outlet 188. The disentrained dirt particles and debris may discharge from cyclone chamber 154 through a dirt outlet 190 into dirt collection chamber 156 external to the cyclone chamber 154, where the dirt particles and debris may collect until dirt collection chamber 156 is emptied.

Air exiting cyclone chamber 154 may pass through an outlet passage 192 located upstream of cyclone air outlet 188. Cyclone chamber outlet passage 192, may also act as a vortex finder to promote cyclonic flow within cyclone chamber 154. In some embodiments, cyclone outlet passage 192 may include a porous member such as a screen or shroud 196 (e.g. a fine mesh screen) in the air flow path 124 (e.g., positioned between the cyclone chamber and an inlet of the vortex finder) to remove large dirt particles and debris, such as hair, remaining in the exiting air flow. The vortex finder and porous member may be spaced from the cyclone chamber face of plate 216. It will be appreciated that, in some embodiments, only a screen may be provided. Alternately a vortex finder may be provided without a screen or the like.

From cyclone air outlet 188, the air flow may be directed into pre-motor filter housing 164 at an upstream side 204 of pre-motor filter 160. The air flow may pass through pre-motor filter 160 to pre-motor filter downstream side 208, and then exit through pre-motor filter chamber air outlet 212 into motor housing 148. At motor housing 148, the clean air flow may be drawn into suction motor 144 and then discharged from apparatus 100 through clean air outlet 120.

Axially Stepped Arrester

The following is a description of a dirt arrester plate (also referred to as a “dirt arrester”, “arrester plate”, or simply “plate”) that separates the cyclone chamber from the dirt collection chamber that may be used in any cyclone design. In accordance with this feature, the dirt collection chamber is external to the cyclone chamber and the dirt outlet from the cyclone chamber comprises or consists of a gap between the arrester plate and the cyclone chamber sidewall. In accordance with this design, the arrester plate has an ‘axial step’, in which a portion of the arrester plate is axially recessed to create an axially recessed step. The axial step may create a relatively larger dirt outlet gap between the cyclone chamber sidewall and the stepped portion of the arrester plate periphery, which can allow larger debris to pass through the dirt outlet.

Without being limited by theory, as compared with an entirely planar arrester plate having a generally uniformly sized dirt outlet gap, the axially stepped arrester design may provide greater separation efficiency (i.e. percentage of dirt particles of a dirty air flow separated from the air flow and retained in the dirt collection chamber) by permitting larger dirt particles to exit the cyclone chamber thereby reducing the likelihood that larger dirt particles in the cyclone chamber may produce eddy currents or otherwise interfere with the flow pattern in a cyclone chamber. Thus, the axially stepped arrester design may allow the dirt collection chamber to admit large dirt particles (e.g. stones, dry foods, etc.) while providing a high separation efficiency.

Reference is now made to FIGS. 3-5. As shown, cyclone bin assembly 116 includes an arrester plate 216 that separates cyclone chamber 154 from dirt collection chamber 156. Arrester plate 216 also cooperates with cyclone 152 to define dirt outlet 190 from cyclone chamber 154 into dirt collection chamber 156.

Arrester plate 216 may define at least part of an end wall for one or both of cyclone 152 and dirt collection chamber 156. As shown, arrester plate 216 may have a cyclone chamber face 220 that borders cyclone chamber 154, and an opposite dirt chamber face 224 that borders dirt collection chamber 156. Cyclone chamber face 220 may face towards an interior volume of cyclone chamber 154. Similarly, dirt chamber face 224 may face towards an interior volume of dirt collection chamber 156.

Cyclone 152 has a first end 228 having a first end wall 232, a second end 236 axially spaced apart from first end 228, and a cyclone chamber sidewall 240 positioned between the first and second ends 228 and 236. Cyclone 152 also has a central longitudinal axis 242 (also referred to as a “cyclone axis”) that extends from the first end 228 to the second end 236. In the example shown, cyclone second end 236 may be defined at least in part by cyclone chamber face 220 of arrester plate 216. In some embodiments, at least a portion of cyclone chamber face 220 faces (i.e. has a surface normal pointed towards) cyclone first end 228. It will be appreciated that, if plate 216 is spaced from sidewall 240, then sidewall 240 will not extend to plate 216. In some embodiments, a portion of plate 216 may abut portions of sidewall 240 while another portion, e.g., the stepped down portion, may be spaced from sidewall 240 to define part or all of the dirt outlet.

Still referring to FIGS. 3-5, cyclone outlet passage 192 may define a vortex finder that promotes cyclonic flow within cyclone chamber 154. As shown, cyclone outlet passage 192 may extend from a first end 244 at cyclone first end 228, to a second end 248 within cyclone chamber 154. Cyclone outlet passage 192 has one or more inlet openings 252 that admit air exiting cyclone chamber 154 to enter cyclone outlet passage 192 towards cyclone air outlet 188. Cyclone outlet passage opening(s) 252 may be overlaid with a porous member 254 (e.g. a fine mesh screen), which may remove large dirt and debris from the air flow entering the cyclone outlet passage 192. As shown, cyclone outlet passage 192 and porous member 254 may be spaced (e.g. axially) from cyclone chamber face 220 of arrester plate 216. Cyclone outlet passage 192 may be intersected by cyclone axis 242. As shown, cyclone outlet passage 192 may have a central longitudinal axis 256 that is parallel to cyclone axis 242 (e.g. collinear to cyclone axis 242, or spaced apart from cyclone axis 242).

It will be appreciated that any cyclone air outlet may be used and that the cyclone air outlet may be at various locations as is known in the art. Similarly, it will be appreciated that any cyclone air inlet 184 may be used and that the cyclone air inlet may be at various locations as is known in the art.

Dirt collection chamber 154 has a first end 260, a second end 264 axially spaced apart from first end 260, and a sidewall 268 that extends between the first and second ends 260 and 264. Dirt collection chamber 154 has a longitudinal axis 272 (also referred to as a “dirt chamber axis”). Dirt chamber axis 272 may be parallel to cyclone axis 242 (e.g. collinear to cyclone axis 242, or transversely spaced apart from cyclone axis 242). Dirt chamber first end 260 may be defined at least in part by dirt chamber face 224 of arrester plate 216. Dirt chamber second end 264 may include a second end wall 276. In some embodiments, at least a portion of dirt chamber face 224 faces (i.e. has a surface normally pointed towards) dirt chamber second end 264.

As used herein, the term “axial” and “axially” mean “in a direction parallel to the respective longitudinal axis”, such as for example cyclone axis 242 or dirt chamber axis 272. For example, dirt chamber face 224 may be described as being axially spaced apart from cyclone chamber face 220 in that dirt chamber face 224 is spaced from cyclone chamber face 220 in a direction parallel to or along the cyclone axis 242.

Referring to FIGS. 8-9, cyclone dirt outlet 190 may extend around all of arrester plate periphery 288. As shown, every point on arrester plate periphery 288 may have a (non-zero) dirt outlet gap length 292 to cyclone chamber sidewall 240. In this way, dirt outlet 190 may form a continuous annular gap. This helps to mitigate the development of blockages caused by an accumulation of debris at locations where there is no dirt outlet 190, e.g. because the dirt outlet 190 is obstructed. In other embodiments, arrester plate 216 may about part of sidewall 240.

Referring to FIGS. 3 and 6, arrester plate 216 may be movable between a closed position (FIG. 3) and an open position (FIG. 6). In the closed position, arrester plate 216 may act to separate cyclone chamber 154 from dirt collection chamber 156. If plate 216 contacts part of sidewall 240, then arrester plate 216 may at least partially close cyclone second end 236 when in the closed position. Alternately, as exemplified in FIGS. 3 and 8-10, plate 216 may be spaced from all of sidewall 240 when in the closed position. In the open position, arrester plate 216 may be positioned to provide user access to cyclone chamber 154 (e.g. for cleaning). For example, arrester plate 216 may close less of or none of cyclone second end 236 when in the open position as compared to the closed position.

As shown, arrester plate 216 may be connected to an openable end wall 276 of dirt collection chamber 156. Arrester plate 216 may move with end wall 276 so that when end wall 276 is opened, arrester plate 216 is displaced from (i.e. moved away from) cyclone second end 236. This allows cyclone chamber 154 and dirt collection chamber 156 to be opened and emptied concurrently by moving end wall 276 from its closed position (FIG. 3) to its open position (FIG. 6). Alternately, plate 216 may be pivotally mounted to sidewall 240, to a sidewall of the dirt chamber,

In some embodiments, plate 216 may not be openable, or it may be openable separately from the dirt chamber. For example, plate 216 may be pivotally mounted to sidewall 240 or to a sidewall of the dirt chamber and may have its own releasable lock. Accordingly, plate 216 may remain in position when end wall 276 is opened and may be separately openable.

Dirt chamber end wall 276 may be openable in any manner that allows access to empty dirt collection chamber 156. For example, dirt chamber end wall 276 may be pivotally openable as shown, or removable from dirt collection chamber 156. In the illustrated example, dirt chamber end wall 276 is rotatably connected to dirt collection chamber sidewall 268 by a hinge 280, and releasably held in the closed position (FIG. 3) by a latch 284.

Arrester plate 216 may be connected to dirt chamber end wall 276 in any manner that allows arrester plate 216 to open concurrently as dirt chamber end wall 276 is opened. In the illustrated example, arrester plate 216 is connected to dirt chamber end wall 276 by a rigidly mounted support member 286. Accordingly, support member 286 may be a post that rigidly connects arrester plate 216 to dirt chamber end wall 276, whereby arrester plate 216 and dirt chamber end wall 276 move as one. In some embodiments, support member 286 may be moveable (pivotally) mounted with respect to end wall 276 and/or plate 216 may be moveable (pivotally) mounted with respect to support 268. As shown, support member 286 may extend from dirt chamber face 224 of arrester plate 216 to dirt chamber end wall 276. In this example, at least a portion of dirt chamber end wall 276 faces (i.e. has a surface normal pointed towards) arrester plate 216 (e.g. towards dirt chamber face 224).

Returning to FIGS. 3-5, cyclone dirt outlet 190 may be formed by a gap between cyclone chamber sidewall 240 and the arrester plate 216). Dirt that is disentrained (i.e. separated) from the airflow circulating through cyclone chamber 154 (e.g. by cyclonic action within cyclone chamber 154) may exit cyclone chamber 154 through dirt outlet 190 into dirt collection chamber 156. The maximum size of a dirt particle that can exit through dirt outlet 190 is defined by a gap length 292. Gap length 292 is the shortest distance between a given point on arrester plate 216 and cyclone chamber sidewall 240. There may be a uniform gap length 292 at every point on arrester plate periphery 288, or gap length 292 may vary along arrester plate periphery 288.

As exemplified in FIG. 3, plate 216 may have a diameter similar to the diameter of cyclone chamber 154 and the cyclone axis may intersect the centre of arrester plate 216. Accordingly the arrester plate periphery 288 (also referred to as “arrester plate perimeter”) may underlie the sidewall 240 (i.e., a projection of sidewall 240 may intersect the arrester plate periphery 288) such that arrester plate periphery 288 underlies a free end 296 of cyclone chamber sidewall 240. Accordingly, as exemplified in FIG.3, dirt outlet 190 is defined by a gap length 292, which is solely axial. That is, the shortest distance between every point on arrester plate periphery 288 and cyclone chamber sidewall 240 is in a direction parallel to cyclone axis 242.

It will be appreciated that the cross sectional area of plate 216 and the outlet end of the cyclone chamber 154 may vary (e.g., plate 216 may have a diameter that is smaller than or larger than the diameter of cyclone chamber 154). The arrester plate may be coplanar with free end 296 of cyclone chamber sidewall 240 (see for example FIG.7) or is may be axially spaced therefrom (See for example FIG. 8).

FIG. 7 shows an example in which arrester plate 216 has a diameter that is smaller than the diameter of cyclone chamber 154 so that at least a portion of dirt outlet 190 is defined by gap lengths 292 that are solely radial. That is, the shortest distance between at least a portion 304 of arrester plate periphery 288 and cyclone chamber sidewall 240 is in a direction that is transverse (e.g. perpendicular) to cyclone axis 242. As shown, at least portion 304 of arrester plate periphery 288 has the same axial position as a portion of cyclone chamber sidewall 240.

FIG. 8 shows an example in which all of dirt outlet 190 is defined by gap lengths 292 that include radial and axial components. That is, the shortest distance between at least a portion 304 of arrester plate periphery 288 and cyclone chamber sidewall 240 is in a direction that is at a non-zero and non-perpendicular angle (i.e. non-parallel and non-orthogonal) to cyclone axis 242.

Different points on arrester plate periphery 288 may have different dirt outlet gap lengths 292. FIG. 9 shows an example in which arrester plate 216 is off-centered relative to cyclone axis 242 whereby radial gap length 292 is greater at some points along arrester plate periphery 288 than others (e.g. compare gap length 292 ₁ to gap length 292 ₂). Alternatively, or in addition, arrester plate periphery 288 may have an axial shape (i.e. the shape of a projection of arrester plate periphery 288 in a direction parallel to cyclone axis 242) that differs from the axial shape of cyclone chamber sidewall 240 where cyclone chamber sidewall 240 is nearest to arrester plate periphery 288 (e.g. a triangular arrester plate periphery 288 and circular cyclone chamber sidewall 240). This too may produce a variable gap length 292 around arrester plate periphery 288.

Returning to FIGS. 3-5, the illustrated arrester plate 216 is shown including an upper plateau and a peripheral step on one side. The peripheral step can provide an enlarged dirt outlet gap length across only the stepped portion of the dirt arrester periphery. An advantage of this design is that the enlarged dirt outlet gap provides clearance for large dirt particles to pass through the dirt outlet into the dirt collection chamber while optionally maintaining a smaller gap for the remainder of the perimeter of the arrester plate (if the remainder of the arrester plate is spaced from sidewall 240). As compared with a dirt arrester that has a comparably large gap length about the entire arrester plate periphery, the illustrated axially stepped design may mitigate re-entry of dirt from the dirt collection chamber into the cyclone chamber through the dirt outlet because much of the dirt outlet retains a relatively smaller gap length. In laboratory testing, the axially stepped design produced greater dirt separation efficiency as compared with a uniformly planar arrester plate, all else being equal.

As shown, arrester plate 216 includes a first portion 308 and a second portion 312. The first and second portions 308 and 312 are axially spaced apart and joined together by a transition portion 316 positioned between the first and second portions 308 and 312. In the illustrated example, transition portion 316 extends from first portion 308 to second portion 312. First, second, and transition portions 308, 312, and 316 may be integrally formed as shown, or discretely formed and rigidly connected together. At least the first and second portions 308 and 312 each include a portion of arrester plate periphery 288. In the illustrated example, each of the first, second, and transition portions 308, 312, and 316 include a portion of arrester plate periphery 288.

Each of first, second, and transition portions 308, 312, and 316 includes a cyclone chamber face 320 ₁, 320 ₂, and 320 ₃ respectively. Cyclone chamber faces 320 border the inner volume of cyclone chamber 154. As shown, second portion cyclone chamber face 320 ₂ may be axially spaced (i.e. in a direction parallel to cyclone axis 242) apart from first portion cyclone chamber face 320 ₁ in a direction away from cyclone first end 228. Thus, arrester plate second portion 312 forms an axial step from the arrester plate first portion 308. As shown, the axial separation between arrester plate first and second portions 308 and 312 may provide arrester plate periphery 288 with a greater dirt outlet gap length 292 at arrester plate second portion 312 than at arrester plate first portion 308. This allows larger particles to pass through dirt outlet 190 at arrester plate second portion 312, while maintaining a smaller gap at arrester plate first portion 308 to mitigate re-entry of dirt particles from dirt collection chamber 156 into cyclone chamber 154.

As shown, cyclone chamber faces 320 ₁ and 320 ₂ of arrester plate first and second portions 308 and 312 may face towards cyclone first end 228 (e.g. towards cyclone first end wall 232). In the illustrated example, cyclone chamber faces 320 ₁ and 320 ₂ are substantially planar and perpendicular to cyclone axis 242. In other embodiments, one or both of cyclone chamber faces 320 ₁ and 320 ₂ may be non-planar. Alternatively or in addition, one or both of cyclone chamber faces 320 ₁ and 320 ₂ may be non-perpendicular to cyclone axis 242.

Axial separation between cyclone chamber faces 320 ₁ and 320 ₂ may be described by their distances from a reference plane 324 (also referred to as a “transverse plane”), which is perpendicular to cyclone axis 242 and intersects the cyclone, such as at cyclone first end 228. As shown, axial distance 322 ₂ from second portion cyclone chamber face 320 ₂ to reference plane 324 is greater than axial distance 322 ₁ from first portion cyclone chamber face 320 ₁ to reference plane 324.

Transition cyclone chamber face 320 ₃ may extend at a non-zero angle to first and second portion cyclone chamber faces 320 ₁ and 320 ₂. As shown, transition cyclone chamber face 320 ₃ may extend substantially axially (e.g. substantially parallel to cyclone axis 242). In the example shown, transition cyclone chamber face 320 ₃ extends perpendicular to first and second portion cyclone chamber faces 320 ₁ and 320 ₂. As shown, transition cyclone chamber face 320 ₃ may be substantially planar.

In some embodiments, transition cyclone chamber face 320 ₃ may be non-perpendicular to cyclone axis 242. For example, it may extend at an acute angle to each of first and second portion cyclone chamber faces 320 ₁ and 320 ₂. Alternately, or in addition, transition cyclone chamber face 320 ₃ may be non-planar; for example, it may curve from first and second portion cyclone chamber face 320 ₁ to second portion cyclone chamber face 320 ₂. For example, transition cyclone chamber face 320 ₃ may be concave or convex.

Arrester plate second portion 312 may be smaller in size (e.g., cross sectional area in a plane parallel to reference plane 324) than arrester plate first portion 308. An advantage of this design is that it provides arrester plate with an enlarged dirt outlet gap length 292 across less than half of dirt outlet 190. For example, the area of an axial projection of arrester plate second portion 312 may be smaller (e.g., less than 50%, less than 40%, less than 30%, less than 20% or less than 10%) than the area of an axial projection of arrester plate first portion 308. In the illustrated example, the area of an axial projection of arrester plate second portion 312 is less than one half of the area of an axial projection of arrester plate first portion 308. In addition, arrester plate second portion 312 may include less of arrester plate periphery 288 than arrester plate first portion 308 (e.g., less than 50%, less than 40%, less than 30%, less than 20% or less than 10%). In the illustrated example, arrester plate second portion 312 includes less than one quarter of arrester plate periphery 288.

Arrester plate second portion 312 may be laterally offset (i.e. in a direction perpendicular to cyclone axis 242) from cyclone axis 242. As shown, arrester plate second portion 312 is axially spaced from arrester plate first portion 308 along an axial line 326 that is parallel and laterally spaced from cyclone axis 242.

Transition cyclone chamber face 320 ₃ may meet first and second portion cyclone chamber faces 320 ₁ and 320 ₂ at first and second discontinuities 328 ₁ and 328 ₂ respectively. As shown, transition cyclone chamber face 320 ₃ extends between first and second discontinuities 328 ₁ and 328 ₂. First discontinuity 328 ₁ may be positioned between first portion cyclone chamber face 320 ₁ and transition portion cyclone chamber face 320 ₃, and second discontinuity may be positioned between second portion cyclone chamber face 320 ₂ and transition portion cyclone chamber face 320 ₃.

As used herein, a “discontinuity” is a macro-scale deviation or disruption of a surface pattern or shape pattern. For example, first discontinuity 328 ₁ is shown as a 90 degree bend that is a deviation from the planar surface of first portion cyclone chamber face 320 ₁, and second discontinuity is shown as a 90 degree bend that is a deviation of the planar surface of second portion cyclone chamber face 320 ₂. Minor deviations (e.g. seams and clearance gaps between otherwise continuous portions), and micro deviations (e.g. elements of surface texture) are not considered herein to be discontinuities. It will be appreciated that, instead of a 90 degree bend, the discontinuities may be rounded.

It will be appreciated that arrester plate 216 may have a perimeter without any angles or other discontinuities. Arrester plate periphery 288 may therefore have a continuous axial shape (i.e. the shape of a projection of arrester plate periphery 288 in a direction parallel to cyclone axis 242) that is smooth. Accordingly, as shown in plan view in FIG. 9, arrester plate 216 is circular.

It will be appreciated that arrester plate may be of any other shape such as elliptical or polygonal (e.g., hexagonal, square, triangle or the like). For example, as exemplified in FIG. 10, an arrester plate periphery 288 may have a discontinuous axial shape. In the example shown, arrester plate periphery 288 has first and second portions 332 and 336 connected by two discontinuities 340. Discontinuities 340 provide deviations from the regular (e.g. circular) shape of periphery first portion 332, and the regular (e.g. linear) shape of periphery second portion 336. In this example, discontinuities 340 are corners (also referred to as junctures) between first and second portions 332 and 336.

It will be appreciated that arrester plate 216 may have an irregular perimeter. For example, the arrester plate may have a shape wherein part of the plate has been truncated to increase the size of the dirt outlet gap. The truncated portion may be any portion of the plate and may be provided on the second portion. This feature may be used with any plate that has a smooth perimeter or which has a perimeter with discontinuities.

For example, as exemplified in FIG. 10, first and second discontinuities 340 ₁ and 340 ₂ may be provided on arrester plate second portion 312. For example, second portion 336 of arrester plate periphery 288 may border at least a portion of arrester plate second portion 312. As compared to arrester plate 216 were the axial shape of periphery first portion 332 continuous around the entire arrester plate periphery 288 (e.g. fully circular), a plate segment 344 has been removed where periphery second portion 336 truncates the axial shape of periphery first portion 332. As shown, periphery second portion 336 may be formed as a cord (e.g. linear crop) to the circular axial shape of periphery first portion 332. The removal of plate segment 344 may further enlarge dirt outlet gap lengths 292 at arrester plate second portion 312. This allows arrester plate 216 to allow even larger particles to pass through the portion of dirt outlet 190 located between periphery second portion 336 and cyclone sidewall 240, as compared to the same arrester plate 216 with plate segment 344 intact.

It will be appreciated that an arrester plate 216 with an axial step can create a concave (also referred to as ‘hollow’) step volume behind the axial face of the step. Depending on the manner in which the associated cyclone and dirt collection chambers are emptied, fibrous debris (e.g. hair) may snag or accumulate in the step volume when emptying the surface cleaning apparatus. Alternately, a hollow shape of the dirt chamber facing side of plate 216 may create eddy currents or otherwise interfere with dirt settling in the dirt collection chamber. Therefore, in some embodiments the step volume is closed by the dirt chamber face of the arrester plate. Closing the hollow step volume may be used with any axially stepped arrester described herein.

It will be appreciated that the closure portion may underlie or traverse only the transition portion, (e.g., if the transition portion extends at an angle to reference plane 324). Alternately the closure portion my underlie both the transition portion and one or both of the first and second portions. As exemplified in FIGS. 11-19, the closure portion underlies both the transition portion and the first portion. An advantage of this design is that the axial thickness of the second portion is not increased. It will be appreciated that the more of the first portion that the closure portion underlies, the more gradual the angle of the closure portion may be.

Referring to FIGS. 4-5, an example arrester plate 216 is shown including an open step volume 348. Step volume 348 is a hollow volume behind transition portion dirt chamber face 364 ₃. As shown, step volume 348 is bordered by transition portion 316 to one side and by first portion 308 above.

FIGS. 11-13 exemplify an embodiment of arrester plate 216 in which step volume 348 is closed by a closure portion 352 of dirt chamber face 224. As shown, closure portion 352 may be opposed to transition portion cyclone chamber face 320 ₃ and to at least a portion of first portion cyclone chamber face 320 ₁. By closing step volume 348, a smoother dirt chamber face of plate 216 is provided which may reduce eddy currents in the dirt collection chamber and facilitate dirt settling in the dirt collection chamber and not being reintrained into the cyclone chamber.

Closure portion 352 may have any configuration suitable to close step volume 348. In some embodiments, closure portion 352 may be free of concavities (e.g. entirely planar as shown, entirely convex, or include both planar and convex portions). In the illustrated example, closure portion 352 extends from a first end 356 proximate dirt chamber face 364 ₂ of second portion 312 towards or across cyclone axis 242 to second end 360 within dirt chamber face 364 ₁ of first portion 308.

FIGS. 11-13 exemplify an example in which closure portion second end 360 is proximate cyclone axis 242. FIGS. 14-16 exemplify an example of arrester plate 216 in which cyclone axis 288 is located between closure portion first and second ends 356 and 360. FIGS. 17-19 exemplify another example of arrester plate 216 in which cyclone axis 288 is located between closure first and second ends 356 and 360.

Closure portion 352 may extend transverse (i.e. non-parallel) to cyclone axis 242. For example, FIGS. 11-13 and 14-16 show examples of arrester plate 216 in which closure portion 352 is neither parallel nor perpendicular to cyclone axis 242. As shown, closure portion first end 356 may be axially and laterally spaced apart from closure portion second end 360. In the illustrated example, closure portion first end 356 is axially spaced from closure portion second end 360 away from cyclone chamber first end 228. FIGS. 17-19 show an example of arrester plate 216 in which closure portion first end 356 is axially aligned and laterally spaced apart from closure portion second end 360.

Referring again to FIGS. 11-13, closure portion 352 may be oriented so that it diverges from cyclone chamber face 320 ₃ of transition portion 316 in a direction away from arrester plate second portion 312. As shown, closure portion second end 360 may be spaced farther from cyclone chamber face 320 ₃ of transition portion 316 than closure portion first end 356.

Dirt chamber face 224 may have one or more discontinuities. For example, FIGS. 11-13 and 14-16 illustrate arrester plates 216 having a dirt chamber face 224 with a discontinuity 368 at the juncture of closure portion 352 and dirt chamber face 364 ₂ of second portion 312. The discontinuity is preferably rounded so as to avoid a sharp angle. In other embodiments, dirt chamber face 224 may be entirely continuous. For example, FIGS. 17-19 show an arrester plate 216 having a dirt chamber face 224 that is entirely planar. In the illustrated example, dirt chamber face 224 is perpendicular to cyclone axis 242. In other embodiments, dirt chamber face 224 may be oriented non-perpendicular and non-parallel to cyclone axis 242.

Plate first portion 308 may have an axial thickness 372 ₁ greater than axial thickness 372 ₂ of plate second portion 312. FIGS. 17-19 show an example arrester plate 216 having a plate first portion 308 with a uniform thickness 372 ₁ that is greater than thickness 372 ₂ of plate second portion 312. FIGS. 11-13 and 14-16 show example arrester plates 216 having a plate first portion 308 with a thickness 372 ₁ that increases towards transition portion 316. As shown, plate thickness 372 ₁ may increase between closure portion first and second ends 356 and 360 towards first end 356.

While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto. The scope of the claims should not be limited by the preferred embodiments and examples, but should be given the broadest interpretation consistent with the description as a whole. 

1. A surface cleaning apparatus comprising: (a) an air flow path extending from a dirty air inlet to a clean air outlet; (b) a cyclone and a suction motor provided in the air flow path; (c) the cyclone comprising a cyclone chamber having a central longitudinal axis, the cyclone having a first end having a first end wall, an axially spaced apart second end, a cyclone chamber sidewall located between the first and second ends, a cyclone air inlet provided at the first end, a cyclone air outlet provided at the first end and a dirt outlet provided at the second end, wherein a reference plane that is perpendicular to the central longitudinal axis extends through the cyclone chamber; and, (d) a plate located at the second end, the plate having a plate perimeter, a first portion, (i) a second portion and a transition portion provided between the first and second portions, each of the first, second and transition portions of the plate having a cyclone chamber face wherein the cyclone chamber faces of the first and second portions of the plate face towards the first end and border different portions of the plate perimeter, (ii) the second portion is spaced in a direction parallel to the central longitudinal axis further from the reference plane than the first portion, (iii) the dirt outlet comprises a spacing between the cyclone chamber sidewall and the second portion of the plate, (iv) the plate also having a dirt chamber face and a step volume, the step volume positioned axially between the cyclone chamber faces of the first and transition portions and the dirt chamber face whereby the dirt chamber face comprises a closure portion which underlies the step volume; and, (e) a dirt collection region in communication with the cyclone chamber via the dirt outlet.
 2. The surface cleaning apparatus of claim 1 wherein the closure portion extends at an angle to the central longitudinal axis.
 3. The surface cleaning apparatus of claim 1 wherein the first portion of the plate is thicker than the second portion of the plate.
 4. The surface cleaning apparatus of claim 1 wherein a thickness of the first portion of the plate increases towards the transition portion of the plate.
 5. The surface cleaning apparatus of claim 1 wherein a first discontinuity is provided between the cyclone chamber face of the first portion of the plate and the cyclone chamber face of the transition portion and a second discontinuity is provided between the cyclone chamber face of the transition portion and the cyclone chamber face of the second portion of the plate.
 6. The surface cleaning apparatus of claim 5 wherein the transition portion extends generally axially.
 7. The surface cleaning apparatus of claim 6 wherein the first portion of the plate and the second portion of the plate are generally planar.
 8. The surface cleaning apparatus of claim 1 wherein the dirt chamber face of the plate is generally continuous.
 9. The surface cleaning apparatus of claim 1 wherein the dirt collection region is axially spaced from and opposed to the first end of the cyclone.
 10. The surface cleaning apparatus of claim 1, wherein the closure portion is planar.
 11. The surface cleaning apparatus of claim 1, wherein: (a) the closure portion extends from a first end proximate a dirt chamber face of the second portion towards or across the central longitudinal axis to a second end; and, (b) the first end of the closure portion is laterally spaced from the second end of the closure portion.
 12. A surface cleaning apparatus comprising: (a) an air flow path extending from a dirty air inlet to a clean air outlet and including a cyclone chamber and a suction motor; (b) a dirt collection region external to the cyclone chamber; and, (c) a plate positioned between the cyclone chamber and the dirt collection region and defining a dirt outlet from the cyclone chamber to the dirt collection region, the plate having a cyclone chamber face facing the cyclone chamber, an opposed dirt collection face facing the dirt collection region, and first, second, and transition portions, wherein cyclone chamber faces of the first and second portions are connected by a cyclone chamber face of the transition portion and are different axial distances from a transverse plane that extends through the cyclone and that is perpendicular to a central longitudinal axis of the cyclone, and the dirt collection face closes a step volume bordered by the first and transition portions.
 13. The surface cleaning apparatus of claim 12 wherein the first portion of the plate is thicker than the second portion of the plate.
 14. The surface cleaning apparatus of claim 12 wherein the dirt chamber face of the plate is generally continuous.
 15. The surface cleaning apparatus of claim 12 wherein the dirt collection region is axially spaced from and opposed to the first end of the cyclone.
 16. The surface cleaning apparatus of claim 12 wherein a first discontinuity is provided between the cyclone chamber face of the first portion of the plate and the cyclone chamber face of the second portion of the plate.
 17. The surface cleaning apparatus of claim 12 wherein the first portion of the plate and the second portion of the plate are generally planar.
 18. The surface cleaning apparatus of claim 12 wherein the closure portion extends at an angle to the central longitudinal axis.
 19. The surface cleaning apparatus of claim 12, wherein the closure portion is planar.
 20. The surface cleaning apparatus of claim 12, wherein: (a) the closure portion extends from a first end proximate a dirt chamber face of the second portion towards or across the central longitudinal axis to a second end, and, (b) the first end of the closure portion is laterally spaced from the second end of the closure portion. 